1. Field
The present disclosure relates to a battery module, and more particularly, to a battery module that is improved to offset external forces exerted on a rechargeable battery.
2. Description of the Related Technology
In general, a battery module is constructed with multiple rechargeable batteries connected to one another. The rechargeable batteries can be repeatedly charged and discharged due to reversible mutual transformations between chemical energy and electrical energy. Recently, with the increase in development of portable wireless electronic devices, in order to make the devices small in size and light in weight, there is a growing need for a rechargeable battery with high energy density.
Examples of widely used rechargeable batteries include a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium rechargeable battery. In particular, the lithium rechargeable battery has an operation voltage equal to or greater than 3.6V, which is as three times higher than an operation voltage of the nickel-cadmium battery or the nickel-hydrogen battery. Furthermore, due to its high energy density per unit weight, the lithium rechargeable battery is rapidly growing in popularity as a power source of a portable electronic device. The lithium rechargeable battery may be classified as a lithium ion rechargeable battery, a lithium ion polymer battery, or a lithium polymer battery.
A typically rechargeable battery includes an electrode assembly in which a positive electrode and a negative electrode are interposed between a separator, a casing which has a space containing the electrode assembly, and a cap assembly which is joined with the casing so as to seal the casing. The rechargeable battery may be manufactured in various shapes according to the shapes of the electrode assembly and the casing. In general, the rechargeable battery may be a cylindrical type rechargeable battery, a prismatic type rechargeable battery, or a pouch type rechargeable battery.
The battery module having the aforementioned structure, in which a plurality of rechargeable batteries are connected, is widely used not only for small portable electric devices such as a cellular phone, a personal computer, and a camcorder but also for motor driving power sources for hybrid electric vehicles.
External forces generated due to various reasons may be exerted on the battery module. The external forces may adversely affect the respective rechargeable batteries constituting the battery module. For example, the casing of the rechargeable battery may be damaged by the external force. In addition, the electrode assembly located inside the rechargeable battery may be damaged, thereby causing a short circuit.